Food-Grade Superior Stainless Steel - The Hawkins stainless steel pressure cooker body and lid are made from food-grade, 18/8, non-magnetic, superior stainless steel (AISI Grade 304). The '18/8' symbolizes that this stainless steel grade contains 18percent chromium and 8percent nickel, for greater anti-corrosion resistance, and to better withstand the various acids found in many foods such as fruits, meats, milk, and vegetables. It is hence one of the best quality stainless steel grades used for making cooking utensils. Type 304 stainless steel has great strength, which means that, properly used, your Hawkins stainless steel pressure cooker will give you many years of faithful service.5.8 mm Extra-thick, Heat-Diffusing Sandwich Bottom The pressure cooker body and lid are made of food-grade, superior stainless steel for maximum hygiene and durability. On the outside bottom of the pressure cooker, sandwiched between two sheets of stainless steel, is a core of 4.1 mm thick aluminum, which spreads heat quickly and evenly. This means no hotspots - food will not burn or stick. The external base is made of AISI Grade 430 magnetic stainless steel, which means that your Hawkins stainless steel pressure cooker will work on both gas and induction cooktops. The extra-thick base stays flat and never bulges. It can be used safely for light and deep frying before pressure cooking.The Hawkins Pressure-Locked Safety Lid The unique Hawkins pressure-locked safety lid ensures that when there is pressure inside the cooker, the lid is pressure-locked like a modern jetliner door. It cannot be opened until the pressure has fallen to a safe level.